Ablation catheters

ABSTRACT

The present invention relates generally to multifunctional catheters for performing ablation procedures, and more particularly to ablation catheters utilized in the treatment of atrial fibrillation and other cardiac disorders. The present invention eliminates many of the problems associated with previous ablation catheters by providing an ablation treatment not dependent upon continuous lesions.

FIELD OF THE INVENTION

The present invention relates generally to catheters for performingtargeted tissue ablation in a subject. In particular, the presentinvention provides devices comprising wire tipped and umbrella tippedablation catheters, and methods for treating conditions (e.g., cardiacarrhythmias) with these devices.

BACKGROUND OF THE INVENTION

Mammalian organ function typically occurs through the transmission ofelectrical impulses from one tissue to another. A disturbance of suchelectrical transmission may lead to organ malfunction. One particulararea where electrical impulse transmission is critical for proper organfunction is in the heart. Normal sinus rhythm of the heart begins withthe sinus node generating an electrical impulse that is propagateduniformly across the right and left atria to the atrioventricular node.The atrioventricular node in return causes the atria to contract. Atrialcontraction leads to the pumping of blood into the ventricles in amanner synchronous with the pulse.

Atrial fibrillation refers to a type of cardiac arrhythmia where thereis disorganized electrical conduction in the atria causing rapiduncoordinated contractions which result in ineffective pumping of bloodinto the ventricle and a lack of synchrony. During atrial fibrillation,the atrioventricular node receives electrical impulses from numerouslocations throughout the atria instead of only from the sinus node. Thisoverwhelms the atrioventricular node into producing an irregular andrapid heartbeat. As a result, blood pools in the atria that increases arisk for blood clot formation. The major risk factors for atrialfibrillation include age, coronary artery disease, rheumatic heartdisease, hypertension, diabetes, and thyrotoxicosis. Atrial fibrillationaffects 7% of the population over age 65.

Atrial fibrillation treatment options are limited. Lifestyle change onlyassists individuals with lifestyle related atrial fibrillation.Medication therapy assists only in the management of atrial fibrillationsymptoms, may present side effects more dangerous than atrialfibrillation, and fail to cure atrial fibrillation. Electricalcardioversion attempts to restore sinus rhythm but has a high recurrencerate. In addition, if there is a blood clot in the atria, cardioversionmay cause the clot to leave the heart and travel to the brain or to someother part of the body, which may lead to stroke. What are needed arenew methods for treating atrial fibrillation and other conditionsinvolving disorganized electrical conduction.

SUMMARY OF THE INVENTION

The present invention relates generally to catheters for performingtargeted tissue ablation in a subject. In particular, the presentinvention provides devices comprising wire tipped and umbrella tippedablation catheters, and methods for treating conditions (e.g., cardiacarrhythmias) with these devices.

In some embodiments, the present invention provides a device (e.g., forperforming at least one function at an internal site in a subject),comprising an elongate catheter body. The elongate catheter body maycomprise a proximal end, a distal end, and a spiral tip, wherein thespiral tip is configured for tissue ablation. In addition, the spiraltip may be mounted at the distal end of the elongate catheter body. Thespiral tip may be capable of expansion and contraction. In furtherembodiments, the spiral tip may be mounted either centrally orperipherally with the elongate catheter body. In preferred spiral topembodiments, the spiral tip will be configured to create spiral lesionsin targeted body tissue.

In other embodiments, the device may comprise conductive coils on thespiral tip. In particular embodiments, the conductive coils may compriseat least one conductive coil measuring 2-20 millimeters in size.Alternatively, in some embodiments the device may comprise conductiveplates on the spiral tip. In particular embodiments, at least one suchconductive plate may measure 2-20 millimeters in size.

Embodiments with a spiral tip may have the spiral tip positionedperpendicularly to the distal end of the elongate catheter body. Inaddition, in some embodiments, the spiral tip may comprise a pluralityof loops. In further embodiments the spiral tip may have at least onecomplete loop. In other embodiments, the spiral tip loops may beseparated by gaps. In particular embodiments, such gaps may measure lessthan 10 millimeters.

Some embodiments may also comprise a handle attached to the proximal endof the elongate catheter body. In further embodiments, the handle may beconfigured to control expansion or contraction of the spiral tip as wellas flexion and extension of the catheter tip. In yet other embodiments,the device will further comprise an energy source configured to permitemission of energy from the spiral tip.

In some embodiments, the present invention provides an elongate catheterbody, wherein the elongate catheter body comprises a proximal and distalends, and an umbrella tip body. In some embodiments, the umbrella tipbody may comprise a central post, and a plurality outer arms. Inpreferred embodiments, the umbrella tip body is configured for tissueablation. In other embodiments, the umbrella tip body may be mounted atthe distal end of the elongate catheter body.

In some embodiments, the present invention provides a central postextending from distal end of said elongate catheter body. In otherembodiments, the plurality of outer arms may attach at distal andproximal ends of the central post.

In other embodiments, the device may comprise conductive coils on theouter arms. In particular embodiments, the conductive coils may compriseat least one conductive coil measuring 2-20 millimeters in size. Inother embodiments, the conductive coils may comprise at least oneconductive coil measuring 4-8 millimeters in size. Alternatively, insome embodiments the device may comprise conductive plates on the outerarms. In particular embodiments, at least one such conductive plate maymeasure 2-20 millimeters in size. In other embodiments, the conductiveplates may comprise at least one conductive plate measuring 4-8millimeters in size. In preferred embodiments, the umbrella tip may beconfigured to create radial lesions in body tissue.

Some embodiments may also comprise a handle attached to the proximal endof the elongate catheter body. In further embodiments, the handle may beconfigured to control expansion or contraction of the umbrella tip bodyas well as flexion and extension of the catheter tip. In yet otherembodiments, the device will further comprise an energy sourceconfigured to permit emission of energy from the umbrella tip body.

In some embodiments, the present invention provides a method of treatingbody tissues. In such embodiments, the method comprises the steps ofproviding a device, and detailed treatment steps. In other embodiments,the present invention provides a radio-frequency energy source.

In particular embodiments, the device may comprise an elongate catheterbody, wherein the elongate catheter body comprises a proximal end and adistal end, and also a spiral tip, wherein the spiral tip may beconfigured for tissue ablation, the spiral tip mounted at the distal endof the elongate catheter body, and is capable of expansion andcontraction.

In other particular embodiments, the device may comprise an elongatecatheter body, wherein the elongate catheter body comprises a proximalend and a distal end, and also an umbrella tip body, wherein theumbrella tip body may be configured for tissue ablation, the umbrellatip body is mounted at the distal end of the elongate catheter body, andthe umbrella tip body is capable of expansion and contraction. In stillfurther embodiments, the umbrella tip may comprise a central post, and aplurality of outer arms.

In some embodiments, the detailed treatment steps may comprise theinserting of the catheter through a major vein or artery, the guiding ofthe catheter to the selected body tissue site by appropriatemanipulation through the vein or artery, the guiding of the catheter tothe selected body tissue site, the positioning of the device with theselected body tissue; and the releasing of energy from the device intothe body tissue.

In particular embodiments, the detailed treatment steps may be specificfor treating atrial fibrillation, and comprise the inserting of thecatheter through a major vein or artery, the guiding of the catheterinto the atria of the heart by appropriate manipulation through the veinor artery, the guiding of the catheter to the target atrial region, thepositioning the device with the targeted atrial region; and a releasingof energy from the device into the targeted atrial region.

In still further embodiments, the detailed treatment steps may bespecific for treating cardiac arrhythmias, and comprise the inserting ofthe catheter through a major vein or artery, the guiding of the catheterinto the heart by appropriate manipulation through the vein or artery,the guiding of the catheter to the targeted heart region, thepositioning of the device with the targeted heart region; and thereleasing of energy from the device into the targeted heart region.

DESCRIPTION OF THE FIGURES

FIG. 1 shows one wire tip ablation catheter embodiment.

FIG. 2 shows one embodiment of the wire tip ablation catheter.

FIG. 3 shows one embodiment of the wire tip ablation catheter utilizingconductive plates.

FIG. 4 shows one embodiment of the wire tip ablation catheter utilizingconductive coils.

FIG. 5 shows one embodiment of the umbrella tip ablation catheter.

FIG. 6 shows one embodiment of the umbrella tip ablation catheter.

FIG. 7 shows one embodiment of the umbrella tip ablation catheter.

FIG. 8 shows one embodiment of the umbrella tip ablation catheter.

FIG. 9 shows one embodiment of the umbrella tip ablation catheter.

FIG. 10 shows one embodiment of the umbrella tip ablation catheter.

FIG. 11 shows one embodiment of the umbrella tip ablation catheter.

GENERAL DESCRIPTION OF THE INVENTION

The present invention provides catheters for performing targeted tissueablation in a subject. In particular, the present invention providesdevices comprising wire tipped and umbrella tipped catheter ablationdevices, and methods for treating conditions (e.g., super ventriculartachycardia with these devices.

As described above, the normal functioning of the heart relies on properelectrical impulse generation and transmission. In certain heartdiseases (e.g., atrial fibrillation) proper electrical generation andtransmission are disrupted. In order to restore proper electricalimpulse generation and transmission, the catheters of the presentinvention may be employed.

In general, catheter ablation therapy provides a method of treatingcardiac arrhythmias. Physicians make use of catheters to gain accessinto interior regions of the body. Catheters with attached ablatingdevices are used to destroy targeted tissue. In the treatment of cardiacarrhythmias, a specific area of cardiac tissue emitting or conductingerratic electrical impulses is initially localized. A user (e.g., aphysician) will direct a catheter through a main vein or artery into theinterior region of the heart that is to be treated. The ablating elementis next placed near the targeted cardiac tissue that is to be ablated.The physician directs an energy source from the ablating element toablate the tissue and form a lesion. In general, the goal of catheterablation therapy is to destroy cardiac tissue suspected of emittingerratic electric impulses, thereby curing the heart of the disorder. Fortreatment of atrial fibrillation currently available methods have shownonly limited success and/or employ devices that are not practical.

The ablation catheters of the present invention allow the generation oflesions of appropriate size and shape to treat conditions involvingdisorganized electrical conduction (e.g., atrial fibrillation). Theablation catheters of the present invention are also practical in termsof ease-of-use and risk to the patient. In general, no cathetertechnique has been shown to have a high efficacy in treatment ofpersistent atrial fibrillation. Catheters that generate linear orcurvilinear lesions in the left or right atrial tissue have a verylimited efficacy. Moreover, the procedure length and the incidence ofcomplications are significantly high with current approaches. Anotherapproach utilizes encircling of the left atrial tissue by point-by-pointapplications. An additional approach utilizes encircling of the leftatrial tissue by point-by-point applications of radio-frequency energy.However, to generate complete circles this approach is time consumingand has limited efficacy. The present invention addresses this needwith, for example, wire tip and umbrella ablation catheters and methodsof using these ablation catheters to create spiral or radial lesions inthe endocardial surface of the atria by delivery of energy (e.g.,radio-frequency). The lesions created by the wire tipped and umbrellatipped ablation catheters are suitable for inhibiting the propagation ofinappropriate electrical impulses in the heart for prevention ofreentrant arrhythmias.

Definitions

To facilitate an understanding of the invention, a number of terms aredefined below.

As used herein, the terms “subject” and “patient” refer to any animal,such as a mammal like livestock, pets, and preferably a human. Specificexamples of “subjects” and “patients” include, but are not limited, toindividuals requiring medical assistance, and in particular, requiringatrial fibrillation catheter ablation treatment.

As used herein, the terms “catheter ablation” or “ablation procedures”or “ablation therapy,” and like terms, refer to what is generally knownas tissue destruction procedures. Ablation is often used in treatingseveral medical conditions, including abnormal heart rhythms. It can beperformed both surgically and non-surgically. Non-surgical ablation istypically performed in a special lab called the electrophysiology (EP)laboratory. During this non-surgical procedure a catheter is insertedinto the heart and then a special machine is used to direct energy tothe heart muscle. This energy either “disconnects” or “isolates” thepathway of the abnormal rhythm (depending on the type of ablation). Itcan also be used to disconnect the electrical pathway between the upperchambers (atria) and the lower chambers (ventricles) of the heart. Forindividuals requiring heart surgery, ablation can be performed duringcoronary artery bypass or valve surgery.

As used herein, the term “wire tip body” refers to the distal mostportion of a wire tip catheter ablation instrument. A wire tip body isnot limited to any particular size. A wire tip body may be configuredfor energy emission during an ablation procedure.

As used herein, the term “spiral tip” refers to a wire tip bodyconfigured into the shape of a spiral. The spiral tip is not limited inthe number of spirals it may contain. Examples include, but are notlimited to, a wire tip body with one spiral, two spirals, ten spirals,and a half of a spiral.

As used herein the term “umbrella tip body” refers to the distal mostportion of an umbrella tip catheter ablation instrument. An umbrella tipbody is not limited to any particular size. An umbrella tip body may beconfigured for energy emission during an ablation procedure.

As used herein, the term “lesion,” or “ablation lesion,” and like terms,refers to tissue that has received ablation therapy. Examples include,but are not limited to, scars, scabs, dead tissue, and burned tissue.

As used herein, the term “spiral lesion” refers to an ablation lesiondelivered through a wire tip ablation catheter. Examples include, butare not limited to, lesions in the shape of a wide spiral, and a narrowspiral.

As used herein, the term “umbrella lesion” or “radial lesion,” and liketerms, refers to an ablation lesion delivered through an umbrella tipablation catheter. Examples include, but are not limited to, lesionswith five equilateral prongs extending from center point, lesions withfour equilateral prongs extending from center point, lesions with threeequilateral prongs extending from a center point, and lesions with fivenon-equilateral prongs extending from center point.

As used herein, the term “conductive coil” refers to electrodes capableof emitting energy from an energy source in the shape of a coil. Aconductive coil is not limited to any particular size or measurement.Examples include, but are not limited to, densely wound copper, denselywound platinum, and loosely wound silver.

As used herein, the term “conductive plate” refers to electrodes capableof emitting energy from an energy source in the shape of a plate. Aconductive plate is not limited to any particular size or measurement.Examples include, but are not limited to, copper plates, silver plates,and platinum plates.

As used herein, the term “energy” or “energy source,” and like terms,refers to the type of energy utilized in ablation procedures. Examplesinclude, but are not limited to, radio-frequency energy, microwaveenergy, cryo-energy energy (e.g., liquid nitrogen), or ultrasoundenergy.

As used herein, the term “maze procedure,” “maze technique,” “mazeablation,” and like terms, refer to what is generally known as a cardiacablation technique. Small lesions are made at a specific location in theheart in a manner so as to create a “maze.” The maze is expected toprevent propagation of electrical impulses.

As used herein, the term “central post” refers to a chamber capable ofhousing small items. The central post is made from a durable material. Acentral post is not limited to any particular size or measurement.Examples include, but are not limited to, polyurethane, steel, titanium,and polyethylene.

As used herein, the term “outer arms” refers to a shaft capable ofinterfacing with electrodes and a central post. An outer arm is notlimited to any size or measurement. Examples include, but are notlimited, to titanium shafts, polyurethane shafts, and steel shafts.

As used herein, the term “outer arm hinge” refers to a joint (e.g.,junction, flexion point) located on an outer arm. The degree of flexionfor an outer arm hinge may range from 0 to 360 degrees.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides structures that embody aspects of theablation catheter. The present invention also provides tissue ablationsystems and methods for using such ablation systems. The illustrated andpreferred embodiments discuss these structures and techniques in thecontext of catheter-based cardiac ablation. These structures, systems,and techniques are well suited for use in the field of cardiac ablation.

However, it should be appreciated that the invention is applicable foruse in other tissue ablation applications. For example, the variousaspects of the invention have application in procedures for ablatingtissue in the prostrate, brain, gall bladder, uterus, and other regionsof the body, using systems that are not necessarily catheter-based.

The multifunctional catheters of the present invention have advantagesover previous prior art devices. FIGS. 1-11 show various preferredembodiments of the multifunctional catheters of the present invention.The present invention is not limited to these particular configurations.

Wire Tip Ablation Catheters

FIG. 1 illustrates an ablation catheter embodiment including broadly anelongate catheter body 10 (e.g., hollow tube) extending from a handle11. Elongate catheter body 10 permits the housing of items that assistin the ablation of subject tissue (e.g., human tissue and other animaltissue, such as cows, pigs, cats, dogs, or any other mammal). Theelongate catheter body 10 may range in size so long as it is not sosmall that it cannot carry necessary ablation items, and not so large sothat it may not fit in a peripheral major vein or artery. The elongatecatheter body 10 includes an elongate sheath 12 (e.g., protectivecovering). The elongate sheath 12 may be made of a polymeric,electrically nonconductive material, like polyethylene or polyurethane.In preferred embodiments, the elongate sheath 12 is formed with thenylon based plastic Pbax, which is braided for strength and stability.In additional embodiments, the elongate sheath 12 is formed with hypotubing (e.g., stainless steel, titanium). The elongate sheath 12 housesa conducting wire 13 (e.g., standard electrical wire) and a thermalmonitoring circuit 19. The conducting wire extends from the handle 11through the distal opening 14. In addition, the conducting wire 13 iswrapped with a steering spring 15. The conducting wire 13 is flexible sothat it may be flexed to assume various positions (e.g., curvilinearpositions). The steering spring 15 is controlled through manipulation ofthe handle 11, as discussed below. The conducting wire 13 is alsocapable of transmitting energy (e.g., radio-frequency energy) from anenergy source 16 (e.g., radio-frequency energy generator).

A thermal monitoring circuit 19 (e.g., thermocouple) is coupled with theconducting wire 13 and extends from the handle 11 through the umbrellatip body 25. The thermal monitoring circuit 19 connects with energysource cable 23 within handle 11. Regulation of the thermal monitoringcircuit 19 is achieved through the energy source 16. In someembodiments, the present invention utilizes the thermal monitoringcircuit described in U.S. Pat. No. 6,425,894 (herein incorporated byreference), whereby a thermocouple is comprised of a plurality ofthermal monitoring circuits joined in series. The thermal monitoringcircuits are thermoconductively coupled to the electrodes. In someembodiments, the thermal monitoring circuit employs two wires to travelthrough the elongated catheter body in order to monitor a plurality ofelectrodes.

The distal opening 14 is the distal terminus of the elongate catheterbody 10. At the distal opening 14, the conducting wire 13 exits theelongate sheath 12. While the majority of the conducting wire 13 ishoused within the elongate sheath 12, the distal portion is housedwithin the wire tip sheath 17. The wire tip sheath 17 begins at thedistal opening 14 and extends throughout the wire tip body 18. The wiretip sheath 17 may be made of a polymeric, electrically nonconductivematerial (e.g., polyethylene or polyurethane). In preferred embodiments,the wire tip sheath 17 is formed with peek insulator (e.g., hightemperature thermo-plastic). A thermal monitoring circuit 19 is coupledwith the conducting wire 13 and extends from the handle 11 through thewire tip body 18. The thermal monitoring circuit 19 connects with energysource cable 23 within handle 11.

The wire tip sheath 17 permits the wire tip body 18 to be molded orshaped into a desired position. In preferred embodiments, the wire tipbody 18 may be shaped into a unique shape (e.g., spiral).

In the preferred embodiment described FIGS. 1-4, the wire tip body 18 isin the shape of a spiral. The spiral on a wire tip body 18 may beperipheral to or central to the elongate catheter body 10. The spiralwire tip body 18 is central if the spiral interfaces with the distalopening 14 at the spiral center point, and peripheral if the spiralinterfaces with the distal opening 14 at the spiral exterior point. Theembodiment described in FIG. 1 presents a spiral wire tip body 18 thatis peripheral to the elongate catheter body 10. Alternatively, theembodiment described in FIG. 2 presents a spiral wire tip body 18 thatis central to the elongate catheter body. A wire tip body 18 in theshape of a spiral may comprise any number of complete rotations (e.g.,complete spirals). In the embodiment described in FIGS. 1 and 2, thespiral wire tip body 18 consists of two and one half complete rotations.Alternatively, the embodiment described in FIG. 3 presents a spiral withonly two complete rotations. The distance inbetween the spirals on thewire tip body 18 may assume any measurement.

Tissue ablation occurs on the wire tip body 18. Various conductiveelements (e.g., coils or plates) may be distributed along the wire tipbody 18. The energy utilized within a catheter ablation instrument isreleased through the conductive elements. The number of conductiveelements on the wire tip body 18 permit a determined energy release andresulting ablation lesion.

The conductive elements used in the preferred embodiment described inFIGS. 1, 2 and 4 are conductive coils 20. Each conductive coil 20 is anelectrode that is comprised of a densely wound continuous ring ofconductive material, (e.g., silver, copper). In preferred embodiments,the conductive coil 20 is made from platinum. The conductive coils 20are fitted (e.g., pressure fitting) about the wire tip body 18. Inpreferred embodiments, a conductive coil 20 is soldered onto aconductive metal (e.g., copper, copper with silver) and swaged onto thewire tip body 18. Additional embodiments may utilize an adhesive seal inaddition to swaging in fixing conductive coils 20 to the wire tip body18. A conductive coil 20 may range in size from 0.1 mm to 20 mm. Inpreferred embodiments, a conductive coil 20 ranges in size from 2 to 8mm. The conductive coils 20 interact with the conducting wire 13 andemit the energy carried by the conductive wire 13.

Conductive coils 20 may be arranged in many different patterns (e.g.,staggered) along the wire tip body 18. Such patterns may involverepeating sets of conductive coils 20 (e.g., set of 3 coils-3 coils-3coils, etc.) or nonrepeating sets (e.g., set of 3 coils-5 coils-2 coils,etc.). In addition, the pattern of conductive coils 20 may simplyinvolve only one coil instead of sets. The pattern of conductive coils20 arranged in the preferred embodiment presented in FIGS. 1, 2 and 4consist of a repeating set of four conductive coils 20 separated by agap. In general, the gap may range in size from 0.1 mm to 100 mm, and isnonconductive. In the embodiments demonstrated in FIGS. 1, 2 and 4, thegap size is 5 mm. Within a repeating arrangement of conductive coils 20,the spaces in between the conductive coils 20 are also nonconductive andmay range in size from 0.01 mm to 100 mm.

The conductive elements used in the preferred embodiment described inFIG. 3 are conductive plates 21. Each conductive plate 21 is anelectrode that is comprised of a solid ring of conductive material(e.g., platinum). The conductive plates 21 are fitted (e.g., pressurefitting) about the wire tip body 18. Additional embodiments may utilizean adhesive seal in addition to swaging in fixing conductive plates 21to the wire tip body 18. A conductive plate 21 may range in size from0.1 mm to 20 mm. The conductive plates 21 interact with the conductingwire 13 and emit the energy carried by the conductive wire 13.

Conductive plates 21 may be arranged in many different patterns (e.g.,repeating sets) along the wire tip body 18. Such patterns may involve arepeating series of conductive plates 21 separated by spaces (e.g.,plate-space-plate-space-plate; etc.) or a random series (e.g.,space-space-plate-plate-plate-space-plate; etc.). In addition, thepattern of conductive plates 21 may simply involve only one short orextended conductive plate 19. The pattern arranged in the preferredembodiment presented in FIG. 3 consists of four conductive plates 21separated by nonconductive gaps. In general, the gaps may range in sizefrom 0.1 mm to 100 mm. In the FIG. 4 embodiment, the gap size is 5 mm.

The pattern of conductive elements arranged on the wire tip body 18 neednot be restricted to only a certain type. Indeed, the present inventionenvisions a wire tip body 18 with varied patterns of differentconductive elements (e.g., coil-gap-plate-plate-gap-coil-coil; etc.).

The wire tip body 18 may be expanded or contracted through manipulationof the handle 11. In preferred embodiments, the handle 11 connects withthe conducting wire 13 with the steering spring 15 attached onto it. Theconducting wire 13 attaches onto a lever 22 inside the handle 11.Extension of the lever 22 causes a contraction in the steering spring 15attached to the conducting wire 13 resulting in a constricting of thewire tip body 18. Alternatively, constriction of the lever 22 causes thesteering spring 15 to expand.

An alternative embodiment utilizes the steering method described in U.S.Pat. No. 5,318,525 (herein incorporated by reference). In thatembodiment, a catheter tip is deflected by means of a shapable handlecoupled to pull wires fastened to the distal end of the deflectable tip.A core wire extends from the handle to the distal tip, providing finepositioning of the deflectable tip by applying torque through the corewire to the tip. A spring tube is further provided in the deflectabletip for improved torque transmission and kink-resistance. The catheterhas an electrode at the distal end of the deflectable tip forpositioning at a target site and applying RF power to accomplishablation.

In other embodiments, the method of catheter manipulation described inU.S. 2001/0044625 A1 (herein incorporated by reference) is utilized,whereby a control element within the handle is able to flex and deflexthe distal tip. Additional embodiments utilize the method of cathetermanipulation described in U.S. Pat. No. 6,241,728 (herein incorporatedby reference), whereby three handle manipulators permit a distal tip tobe deflected longitudinally, radially, and in a torqued position. Afurther embodiment utilizes the method of catheter manipulationdescribed in U.S. 2001/0029366 A1 (herein incorporated by reference),whereby a rotating cam wheel permits the steering of a distal tip in anydirection. However, other mechanisms for steering or deflecting thedistal end of a catheter according to the present invention may also beemployed. For example, the steering and deflection mechanism as setforth in U.S. Pat. No. 5,487,757 may also be employed to deflect thedistal tip of the catheter, as well as any other knowndeflection/steering mechanism. Similarly, a sliding core wire foradjustment of the radius of curvature of the catheter when deflected mayalso be employed, as also disclosed in U.S. Pat. No. 5,487,757.

In alternative embodiments, the wire tip body 18 may be expanded orcontracted though computer assisted manipulation. In other embodiments,the wire tip body 18 may be manipulated through use of magnetic fields.

The terminus of the conducting wire attaches to an energy source cable23 that establishes a connection with the energy source 16.

Depictions of various degrees of contraction or expansion of the wiretip body 18 in the shape of a spiral are presented in FIGS. 2, 3 and 4.In the fully contracted position, the regions between the spirals on thewire tip body 18 decreases while the spacing in between the conductiveelements remains intact. As the wire tip body 18 becomes more expanded,the regions in between spirals on the wire tip body 18 increases, andthe spacing in between the conductive elements remains intact.

The proximal origin of the conducting wire 13 may be located at thedistal end of the handle 11. At the proximal origin of the conductingwire 13, the conducting wire 13 is connected with an energy source 16(e.g., radio-frequency energy). Embodiments of the present invention mayutilize numerous forms of energy (e.g., radio-frequency energy, liquidnitrogen, saline). In one embodiment, liquid nitrogen is utilized as anenergy source 16 (such embodiments employ a hollow tube that travelsthroughout the catheter to deliver N₂ gas) that freezes a particulartissue region. In an additional embodiment, the energy source 16utilized is a saline irrigation system, whereby saline is flushed outthrough a mesh of electrodes carrying an electric current.

In preferred embodiments, radio-frequency energy is utilized as theenergy source 16. Various radio-frequency energy generators arecommercially available. A large (20×10 cm) ground patch 24 is attachedto the patient's back to complete the circuit. The current travels fromthe tip of the heart to the patch. The amount of energy utilized may becontrolled by adjusting the power output of the energy source 16. Fourparameters may are regulated through the energy source 16: power output,impedance, temperature, and duration of energy application.

The precise pattern of conductive elements assorted on the wire tip body18 along with the shaped configuration of the wire tip body 18 permits aunique type of ablation lesion ranging from long and thin to large anddeep in shape. In addition, numerous types of ablation lesions arepossible for each catheter ablator embodiment through manipulation o thewire tip body 18.

Umbrella Tip Ablation Catheters

FIGS. 5-11 illustrate ablation catheter embodiments including broadly anelongate catheter body 10 (e.g., hollow tube) extending from a handle11. The elongate catheter body 10 includes an elongate sheath 12 (e.g.,protective covering). The elongate sheath 12 houses a conducting wire 13(e.g., standard electrical wire) and a thermal monitoring circuit 19.The conducting wire extends from the handle 11 through the distalopening 14. The conducting wire 13 is also capable of transmittingenergy (e.g., radio-frequency energy) from an energy source 16 (e.g.,radio-frequency energy generator).

A thermal monitoring circuit 19 (e.g., thermocouple) may be coupled withthe conducting wire 13 and extend from the handle 11 through theumbrella tip body 25. The thermal monitoring circuit 19 is connects withenergy source cable 23 within handle 11. Regulation of the thermalmonitoring circuit 19 is achieved through the energy source 16. In someembodiments, the present invention utilizes the thermal monitoringcircuit described in U.S. Pat. No. 6,425,894 (herein incorporated byreference), whereby a thermocouple is comprised of a plurality ofthermal monitoring circuits joined in series. The thermal monitoringcircuits thermoconductively coupled to the electrodes. The thermalmonitoring circuit will require only two wires to travel through theelongated catheter body in order to monitor a plurality of electrodes.

The distal opening 14 is the distal terminus of the elongate catheterbody 10. The most distal portion of this embodiment is the umbrella tipbody 25. The umbrella tip body 25 consists of a central post 26, aplurality of outer arms 27, the conductive wire 13, and conductiveelements (e.g., coils).

The central post 26 extends from the distal opening 14. The central post26 is a chamber (e.g., hollow tube) capable of housing small items(e.g., wire). The central post 26 may be made from electricallynonconductive materials (e.g., polyurethane, plastic, or polyethylene).The length of the central post 26 may range from 0.1 mm to 100 mm, andits diameter from 0.001 mm to 100 mm. The central post 26 may be formedinto numerous shapes. In the preferred embodiments described in FIGS.5-11, the central post 26 is in the shape of an extended cylindricalrod.

One function of the central post 26 is to house the conducting wire 13.At the distal opening 14, the conducting wire 13 exits the elongatesheath 12. While the majority of the conducting wire 13 is housed withinthe elongate sheath 12, the distal portion is housed within the centralpost 26.

The outer arms 27 extend from the base of the central post 26 throughthe top of the central post 27. An outer arm 27 is a shaft (e.g., post)made from an electrically nonconductive material (e.g., polyurethane,polyethylene). The length of an outer arm 27 may range from 0.1 mm to100 mm, and its diameter from 0.001 mm to 100 mm. In some embodiments,along the outside of an outer arm 27 is a thermal monitoring circuit 19,which is able to detect temperature and maintain temperature.

An outer arm 27 may be flexible or rigid. In the preferred embodimentsdescribed in FIGS. 5-11, the outer arms 27 are flexible. The degree offlexibility may range from 0 to 360 degrees. There are several types ofouter arm 27 flexibility. The outer arm 27 flexibility displayed inFIGS. 5-11 arises from an outer arm hinge 28 located at the outer arm's27 midpoint and permits a degree of flexibility from 0 to 180 degrees.

One function of the outer arms 27 is to interact with the central post26. The central post 26 and each outer arm 27 firmly connect (e.g.,adhere) at the top of the central post 26. The outer arms 27 alsointerface (e.g., connect) at the base of the central post 26. The outerarm 27 connections at the base of the central post 26 may or may notalso connect with the central post 27. In the preferred embodimentsdescribed in FIGS. 5-11, the outer arms 27 interface together at thedistal opening 14 at a distal opening ring 29. The distal opening ring29 does not connect to the central post 26, but rather connects to thedistal opening 14.

Umbrella tip bodies 26 may present a plurality of outer arms 27. Theembodiments described in FIGS. 5, 10 and 11 display an umbrella tip 26with five outer arms 27. The embodiments described in FIGS. 6 and 7display an umbrella tip body 26 with three outer arms 27. Theembodiments described in FIGS. 8 and 9 display an umbrella tip body 26with four outer arms 27. There may be any range of distances in betweeneach outer arm 27 on an umbrella tip 26. In the embodiments displayed inFIGS. 5-11 the distances in between each outer arm 27 are equilateral.

Conductive elements (e.g., plates) are distributed along the outer arms27. The energy utilized within a catheter ablation instrument isreleased through the conductive elements. The number of conductiveelements an outer arm 27 permits a determined energy release andresulting ablation lesion.

The conductive elements used in the preferred embodiments described inFIGS. 5, 6, 8, and 10 are conductive coils 20. Each conductive coil 20is an electrode that is comprised of a densely wound continuous ring ofconductive material, (e.g., silver, copper). In preferred embodiments,the conductive coil 20 is made from platinum. The conductive coils 20are fitted (e.g., pressure fitting) about the wire tip body 18. Inpreferred embodiments, a conductive coil 20 is soldered onto aconductive metal (e.g., copper, copper with silver) and swaged onto theumbrella tip body 25. Additional embodiments may utilize an adhesiveseal in addition to swaging in fixing conductive coils 20 to theumbrella tip body 25. A conductive coil 20 may range in size from 0.1 mmto 20 mm. The conductive coils 20 interact with the conducting wire 13and emit the energy carried by the conductive wire 13.

Conductive coils 20 may be arranged in many different patterns (e.g.,staggered) along an outer arm 27. Such patterns may involve repeatingsets of conductive coils 20 (e.g., set of 3 coils-3 coils-3 coils, etc.)or nonrepeating sets (e.g., set of 3 coils-5 coils-2 coils, etc.). Thepattern of conductive coils 20 may simply involve only one coil insteadof sets. In addition, an umbrella tip body 26 may vary the patterns ofconductive coils 20 on each outer arm 27 to achieve an even more uniqueablation lesion. The pattern of conductive coils 20 arranged in thepreferred embodiment presented in FIGS. 5, 6, 8, and 10 consist of twosets of four conductive coils 20 separated by a gap on each outer arm 27located near the distal ending. In general, the gaps may range in sizefrom 0.1 mm to 100 mm, and is nonconductive. Within a repeatingarrangement of conductive coils 20, the spaces in between the conductivecoils 20 are also nonconductive and may range in size from 0.01 mm to100 mm.

The conductive elements used in the preferred embodiment described inFIGS. 7, 9, and 11 are conductive plates 21. Each conductive plate 21 isan electrode that is comprised of a solid ring of conductive material,(e.g., platinum). The conductive plates 21 are fitted (e.g., pressurefitting) about an outer arm 27. A conductive plate 21 may range in sizefrom 0.1 mm to 20 mm. The conductive plates 19 interact with theconducting wire 13 and emit the energy carried by the conductive wire13.

Conductive plates 21 may be arranged in many different patterns (e.g.,repeating sets) along an outer arm 27. Such patterns may involve arepeating series of conductive plates 21 separated by spaces (e.g.,plate-space-plate-space-plate; etc.) or a random series (e.g.,space-space-plate-plate-plate-space-plate; etc.). The pattern ofconductive plates 21 may simply involve only one short or extendedconductive plate 21. In addition, an umbrella tip body 26 may vary thepatterns of conductive plates 21 on each outer arm 27 to achieve an evenmore unique ablation lesion. The pattern arranged in the preferredembodiment presented in FIGS. 7, 9, and 11 consists of one conductiveplates 21 on each outer arm 27 located near the distal ending.

The pattern of conductive elements arranged on the umbrella tip body 26need not be restricted to only a certain type. Indeed, the presentinvention contemplates an umbrella tip 26 with varied patterns ofdifferent conductive elements (e.g., outer arm 1: coil-plate-plate-coil;outer arm 2: plate-plate-coil; outer arm 3: coil-coil; etc.).

An umbrella tip 26 may be expanded or contracted through manipulation ofthe handle 11. In one type of embodiment, the base of the central post26 interfaces (e.g., adheres) with the conducting wire 14. The distalopening 14 is wide enough for the central post 26 to slide in and out ofthe elongate catheter body 10. Contraction of the umbrella tip 26 occurswhen the central post 26 is extended out of the elongate catheter body10. Expansion of the umbrella tip 26 occurs when the central post 26 isextended into the elongate catheter body 10.

Extension or retraction of the umbrella tip body 26 is manipulatedthrough the handle 11. In preferred embodiments, the handle 11 connectswith the conducting wire 13 and steering spring 15. The conducting wire13 attaches onto a lever 22 inside the handle 11. Extension of the lever22 causes the central post 26 to extend outside of the elongate catheterbody 10. As the central post 26 extends outside the elongate catheterbody 10, the outer arms 27 reduce the degree of flexion. Retraction ofthe lever 22 causes the central post 26 to withdraw inside the elongatecatheter body 10. As the central post 26 withdraws into the elongatecatheter body 10, the outer arms 27 increase the degree of flexion.

An umbrella tip catheter may utilize numerous alternative steeringembodiments, some of which are described above in relation to wire tipablation catheters.

The terminus of the conducting wire attaches to an energy source cable23 which establishes a connection with the energy source 16.

The proximal origin of the conducting wire 13 may be located at thedistal end of the handle 11. At the proximal origin of the conductingwire 13, the conducting wire 13 is connected with an energy source 16.Embodiments of the present invention may utilize numerous forms ofenergy (e.g., radio-frequency energy, ultrasound, laser, liquidnitrogen, saline-mediated).

In preferred embodiments, radio-frequency energy is utilized as theenergy source 16. Various radio-frequency energy generators arecommercially available. A large (20×10 cm) ground patch 24 is attachedto the patient's back to complete the circuit. The current travels fromthe tip of the heart to the patch. The amount of energy utilized may becontrolled by adjusting the power output of the energy source 16. Fourparameters may are regulated through the energy source 16: power output,impedance, temperature, and duration of energy application.

The precise pattern of conductive elements assorted on an umbrella tip26, along with the varying degrees of central post 26 expansion orcontraction, permits a unique type of ablation lesion ranging from longand thin to large and deep in shape.

Alternative Embodiments

The present invention is not limited to wire tip or umbrella tipembodiments. It is contemplated that fragmented ablation lesions may becreated with alternative designs. For example, zig-zag distal bodies,cross-hatch patterns, or other shapes may be utilized so long as theablation lesion that is created is effective in prevention propagationelectrical impulses.

Uses

The multifunctional catheter of the present invention has manyadvantages over the prior art. The heart has four chambers, or areas.During each heartbeat, the two uppers chambers (atria) contract,followed by the two lower chambers (ventricles). A heart beats in aconstant rhythm—about 60 to 100 times per minute at rest. This action isdirected by the heart's electrical system. An electrical impulse beginsin an area called the sinus node, located in the upper part of the rightatrium. When the sinus node fires, an impulse of electrical activityspreads through the right and left atria causing them to contract,forcing blood into the ventricles. Then the electrical impulses travelin an orderly manner to another area called the atrioventricular (AV)node and HIS-Purkinje network. The AV node is the electrical bridge thatallows the impulse to go from the atria to the ventricles. TheHIS-Purkinje network carries the impulses throughout the ventricles. Theimpulse then travels through the walls of the ventricle, causing them tocontract. This forces blood out of the heart to the lungs and the body.Each electrical circuit has a wavelength. The wavelength is equivalentto the product of the impulse's conduction velocity and the impulse'seffective refractory period.

Atrial fibrillation is the most common type of irregular heartbeat. Inatrial fribrillation, an electrical impulse does not travel in anorderly fashion through the atria. Instead, many impulses begin andspread through the atria and compete for a chance to travel through theAV node. Such aberrant electrical impulses may originate from tissuesother than the heart's electrical system.

One method of treatment for atrial fibrillation is ablation therapy. Itis estimated that for initiation of atrial fibrillation, prematuredepolarizations from any cardiac structure is necessary. However, forperpetuation of atrial fibrillation both a continuous/continual surge ofpremature depolarizations and an atrial substrate capable of maintainingmultiple reentrant circuits of atrial fibrillation are necessary. Thegoal of ablation therapy is to eliminate the premature depolarizationsthat trigger atrial fibrillation, and also to modify the atrial tissuesuch that the minimum wavelength of a reentrant electrical circuit willnot be able to fit into the atrial tissue.

Procedurally, to eliminate triggers, a specific and localized area ofinterest (e.g., area of pulmonary vein connecting with atria, alternategroup of cells emitting electrical impulses on their own) is targeted. Acatheter with an ablation instrument is directed through a major vein orartery to the targeted location in the left atrium. Through the ablationinstrument, radio-frequency is released onto the targeted location. Aresulting scar or lesion is created. To modify the atrial substrate“maze” patterns of ablation lesions are created. The intent is to createcontinuous lesions without any connecting gaps.

The major shortcoming of present ablation techniques is an inability toavoid gaps in the maze ablation process. The heart walls have extremelycomplex curvatures making the creation of a continuous ablation mazenearly impossible. The typical result is an ablation maze containingnumerous gaps. It is important to avoid the presence of gaps within theablation maze because aberrant electrical impulses are able to propagatethrough them resulting in secondary arrhythmias. As such, gaps becomereentrant circuits, and the atrial fibrillation is capable of continuingand different arrhythmias such as atrial flutter may also occur. Inaddition, creation of maze like lesions in atrium is extremely timeconsuming and is associated with a significant complication rate.

The present multifunctional catheter overcomes the gap problem faced inthe prior art by not relying upon continuous lesions. The presentinvention creates spiral or umbrella shaped ablation lesions with verysmall gaps between the ablation lesions. Each gap is not large enough toallow an electrical impulse to propagate through it. The ablation tipsof the present invention (e.g., wire tip or umbrella tip) have arelatively small surface area (e.g., 10-25 mm in diameter). In addition,the tips are pliable and soft, and yet have good support form the shaft.Thus, when the tip is pushed against the atrial wall, most, if not all,of the surface will form good contact without the risk of perforation asit is not a pointed catheter tip. Strategic placement of such ablationlesions essentially decreases the effective atrial mass that an aberrantelectrical impulse may propagate through. This represents a significantimprovement over the prior art because no longer will the laborious andoften unsuccessful creation of ablation lesion mazes be necessary. It isalso possible to use the ablation approach described in this disclosurein conjunction with ablation strategies that target elimination oftriggers such as a pulmonary vein isolation procedure.

The present ablation catheters may be utilized in treating cardiacdisorders including, but not limited to, atrial fibrillation, multifocalatrial tachycardia, inappropriate sinus tachycardia, atrial tachycardia,ventricular tachycardia, ventricular tachycardia, and WPW. In addition,the present ablation catheter may be utilized in several other medicaltreatments (e.g., ablation of solid tumors, destruction of tissues,assistance in surgical procedures, kidney stone removal).

All publications and patents mentioned in the above specification areherein incorporated by reference. Various modifications and variationsof the described devices, compositions, methods, systems, and kits ofthe invention will be apparent to those skilled in the art withoutdeparting from the scope and spirit of the invention. Although theinvention has been described in connection with specific preferredembodiments, it should be understood that the invention as claimedshould not be unduly limited to such specific embodiments. Indeed,various modifications of the described modes for carrying out theinvention that are obvious to those skilled in art are intended to bewithin the scope of the following claims.

1-46. (canceled)
 47. A device comprising: an elongate catheter body,wherein said elongate catheter body comprises a proximal end and adistal end, and an umbrella tip body; said umbrella tip body comprises aplurality of outer arms; wherein said umbrella tip body is configuredfor tissue ablation; wherein said umbrella tip body is mounted at saiddistal end of said elongate catheter body.
 48. The device of claim 47,further comprising a central post having a distal end and a proximalend, wherein said central post extends from said distal end of saidelongate catheter body.
 49. The device of claim 48, wherein saidplurality of outer arms attach at said distal and proximal ends of saidcentral post.
 50. The device of claim 47, wherein said device furthercomprises conductive coils on said plurality of outer arms.
 51. Thedevice of claim 50, wherein said conductive coils comprise at least atleast one conductive coil measuring 4-10 millimeters in size.
 52. Thedevice of claim 47, wherein said device further comprises conductiveplates on said plurality of outer arms.
 53. The device of claim 52,wherein said conductive plates comprise at least one conductive platemeasuring 2-20 millimeters in size.
 54. The device of claim 47, whereinsaid umbrella tip is configured to create radial lesions in body tissue.55. The device of claim 47, further comprising a handle; wherein saidhandle is attached to said proximal end of said elongate catheter body.56. The device of claim 55, wherein said handle is configured to controlexpansion and contraction of said umbrella tip body.
 57. The device ofclaim 47, wherein said device further comprises an energy sourceconfigured to permit emission of energy from said umbrella tip body. 58.The device of claim 47, wherein the umbrella tip body defines a surfacearea between 10 and 25 square mm.
 59. The device of claim 47, whereinthe umbrella tip body may be expanded and contracted.
 60. The device ofclaim 48, wherein the central post is hollow.
 61. The device of claim 60further comprising energy carrying conduits which pass through thecentral post.
 62. The device of claim 48, wherein the central post isconstructed of non-conductive material.
 63. The device of claim 62,wherein the non-conductive material is selected from the groupconsisting of: polyurethane; plastic; polyethylene; and combinationsthereof.
 64. The device of claim 48, wherein the central post length isbetween 0.1 and 100 mm long.
 65. The device of claim 48, wherein thecentral post has a diameter between 0.001 and 100 mm.
 66. The device ofclaim 48, wherein the central post has the geometry of a cylindricalrod.
 67. The device of claim 48, wherein the elongate catheter bodyincludes a lumen from the proximal end to the distal end, and thecentral post can be retracted to be located with said lumen.
 68. Thedevice of claim 67, wherein retraction of the central post causes theflexion angle to increase.
 69. The device of claim 47, wherein theumbrella tip body includes between 2 and 5 outer arms.
 70. The device ofclaim 47, wherein the distance between a first outer arm and anotherouter arm is different than the distance between a second outer arm andanother outer arm.
 71. The device of claim 47, wherein the distancebetween each sequential outer arm is substantially equal.
 72. The deviceof claim 48, wherein the outer arms include a shaft which is fixedlyattached to the central post and one or more conductive elements. 73.The device of claim 48, wherein at least one outer arm attaches to thetop end of the central post.
 74. The device of claim 48, wherein atleast one outer arm attaches to a ring.
 75. The device of claim 74wherein the ring is mounted at the distal end of the elongate catheterbody.
 76. The device of claim 47, wherein at least one outer arm isconstructed of non-conductive materials.
 77. The device of claim 76wherein at least one outer arm is constructed of materials selected fromthe group consisting of: polyurethane; polyethylene; and combinationsthereof.
 78. The device of claim 47, wherein at least one outer arm hasa length between 0.1 and 100 mm.
 79. The device of claim 47, wherein theumbrella tip body defines a surface area between 0.03 square millimetersand 314 square centimeters.
 80. The device of claim 47, wherein at leastone outer arm has a diameter greater than about 0.001.
 81. The device ofclaim 47, wherein at least one outer arm further includes a thermalmonitoring circuit component along its length.
 82. The device of claim81, wherein the thermal monitoring circuit is used to detect andmaintain temperatures during tissue ablation.
 83. The device of claim47, wherein at least one outer arm is flexible.
 84. The device of claim47, wherein at least one outer arm is rigid.
 85. The device of claim 47,wherein at least one outer arm includes a bend point along its length.86. The device of claim 85, wherein the bend point is near the midpointof said at least one outer arm.
 87. The device of claim 85, wherein thebend point allows one hundred and eighty degrees of flexion.
 88. Thedevice of claim 47, further comprising at least one conductive elementlocated on an outer arm.
 89. The device of claim 47, wherein said deviceis configured such that a lesion shape is determined by one or more of:a configuration of conductive elements on the umbrella tip; a selectionof conductive elements to be energized; an amount of umbrella expansionand/or contraction; and combinations thereof.
 90. The device of claim88, wherein the at least one conductive element is an electrode.
 91. Thedevice of claim 88, wherein the at least one conductive element releasesenergy.
 92. The device of claim 47, wherein an outer arm includes atleast two conductive elements separated by a gap distance.
 93. Thedevice of claim 92, wherein the gap distance is between 0.1 and 100 mm.94. The device of claim 47, wherein an outer arm includes a firstconductive element, a second conductive element and a third conductiveelement, and wherein the first and second conductive elements areseparated by a distance less than the distance separating the second andthird conductive elements.
 95. The device of claim 88, wherein the atleast one conductive element is pressure fit to the outer arm.
 96. Thedevice of claim 88, wherein the at least one conductive element issoldered and swaged to the outer arm.
 97. The device of claim 88,wherein the at least one conductive element is mechanically fixed to theouter arm with an adhesive.
 98. The device of claim 88, wherein the atleast one conductive element ranges in size from 0.1 to 20 mm.
 99. Thedevice of claim 47, wherein an outer arm includes at least threeconductive elements fixedly attached to said outer arm in a staggeredpattern.
 100. The device of claim 47, wherein an outer arm includes atleast two sets of conductive elements, each of said sets including thesame number of conductive elements.
 101. The device of claim 100,wherein at least one set is limited to a single coil.
 102. The device ofclaim 47, wherein an outer arm includes at least two sets of conductiveelements, said sets including different numbers of conductive elements.103. The device of claim 102 wherein at least one set is limited to asingle coil
 104. The device of claim 47, wherein a first outer armincludes one pattern of one or more conductive elements and a secondouter arm includes a different pattern of conductive elements.
 105. Thedevice of claim 88, wherein the conductive element comprises acontinuous ring of densely wound wire.
 106. The device of claim 105,wherein the wire is constructed of materials selected from the groupconsisting of: silver; copper; platinum; and combinations thereof. 107.The device of claim 105, wherein the continuous ring is constructed of:densely wound copper wire; densely wound platinum wire; loosely woundsilver wire; and combinations thereof.
 108. The device of claim 88,wherein the conductive element comprises a conductive plate.
 109. Thedevice of claim 88, wherein the conductive element comprises a solidring of conductive material.
 110. The device of claim 88, wherein theconductive element is constructed of materials selected from the groupconsisting of: copper; silver; platinum; and combinations thereof. 111.The device of claim 88, comprising multiple conductive elements and atleast two of said conductive elements are conductive plates withdifferent lengths.
 112. The device of claim 108, comprising twoconductive plates, wherein a first conductive plate is fixedly mountedto a first outer arm and a second conductive plate is fixedly mounted toa second outer arm.
 113. The device of claim 112, wherein the firstconductive plate is mounted near the distal end of the first outer arm.114. The device of claim 88, comprising multiple conductive elementsincluding both conductive plates and conductive coils.
 115. The deviceof claim 114, wherein the number of conductive elements receiving energyis chosen to deliver a predetermined amount of energy.
 116. The deviceof claim 88, wherein a conductive wire is electrically connected to theat least one conductive element.
 117. The device of claim 116, wherein asteering spring is attached to the conductive wire.
 118. The device ofclaim 47, further comprising a handle on the proximal end of thecatheter body, said handle operably attached to the conductive wiressuch that force applies to said wires causes expansion and contractionof the umbrella tip body.
 119. The device of claim 47, furthercomprising a handle on the proximal end of the catheter body, saidhandle including controls to expand or contract the umbrella tip body.120. The device of claim 47, wherein said device is used to create anumbrella lesion.
 121. The device of claim 47, wherein said device isused to create multiple radial lesions.
 122. The device of claim 121,wherein said device is used to create multiple radial lesionssimultaneously.
 123. The device of claim 122, wherein said devicecreates multiple radial lesions without repositioning the umbrella tipbody on the tissue.
 124. The device of claim 47, wherein said device isconfigured to create a series of elongate lesions with small or no gapsin between at least two lesions.
 125. The device of claim 47, whereinsaid device is configured to creates lesions ranging from long and thinto large and deep.
 126. The device of claim 47, wherein said device isconfigured to allow manipulation of the umbrella tip to create variedpatterns of lesions.
 127. The device of claim 47, wherein said device isconfigured to allow an operator to create a maze of lesions.
 128. Thedevice of claim 47, wherein said device is configured to create lesionsto provide treatment for one or more of: atrial fibrillation; multifocalatrial tachycardia; inappropriate sinus tachycardia; atrial tachycardia;ventricular tachycardia; ventricular tachycardia; Wolff-Parkinson-WhiteSyndrome; and supraventricular tachycardia.
 129. The device of claim 47,wherein said device is configured to create lesions located in one ormore of: heart; prostate; brain; gall bladder; and uterus.
 130. Thedevice of claim 47, further comprising an energy source.
 131. The deviceof claim 130, wherein the energy source provides energy selected fromthe group consisting of: microwave energy; cryoenergy; ultrasoundenergy; ultrasound energy; radiofrequency energy; and combinationsthereof.
 132. The device of claim 131, further comprising a flow tubeconfigured to deliver nitrogen to ablate tissue.
 133. The device ofclaim 131, further comprising a metallic mesh, said device configured toapply electric current to said mesh as saline passes therethrough. 134.The device of claim 130, wherein the energy source providesradiofrequency energy, said device configured to regulate parametersselected from the group consisting of: power output; impedance;temperature; duration of energy application; and combinations thereof.135. The device of claim 47, further comprising a thermal monitoringcircuit.
 136. The device of claim 135, wherein the thermal monitoringcircuit comprises a plurality of circuits joined in series.
 137. Thedevice of claim 135, further comprising at least one conductive elementconfigured to deliver energy to ablate the tissue, wherein the thermalmonitoring circuit is thermally coupled to said at least one conductiveelement.
 138. The device of claim 47, further comprising means todeflect the distal end of the catheter body.
 139. The device of claim138, wherein said deflection means is computer assisted.
 140. The deviceof claim 138, wherein said deflection means manipulates the distal endwith magnetic fields.
 141. A tissue ablation device comprising: anelongate catheter body, wherein said elongate catheter body comprises aproximal end and a distal end, and an array of ablation elements mountedto a plurality of arms that extend radially from a central axis of thedistal end of said catheter body, said ablation elements configured fortissue ablation.
 142. The device of claim 141, wherein at least oneouter arm has a length between 0.1 and 100 mm.
 143. The device of claim141, wherein the array of ablation elements defines a surface areabetween 0.03 square millimeters and 314 square centimeters.
 144. Thedevice of claim 141, further comprising a central post having a distaland a proximal end, wherein said central post extends from the distalend of said elongate catheter body.
 145. The device of claim 144,wherein said plurality of outer arms attach at said distal and proximalends of said central post,
 146. The device of claim 141, wherein saidarray of ablation elements is configured to create radial lesions inbody tissue.
 147. The device of claim 141, further comprising a handle;wherein said handle is attached to said proximal end of said elongatecatheter body.
 148. The device of claim 147, wherein said handle isconfigured to control expansion and contraction of said array ofablation elements.
 149. The device of claim 141, wherein said devicefurther comprises an energy source configured to permit emission ofenergy from said array of ablation elements.